ABSTRACT
BACKGROUND:The intestine is not only the main target attacked by sepsis but also the vital organ which mediated sepsis. The recovery of the damaged intestinal barrier structure and function is related to the occurrence and outcome of multiple organ dysfunction syndrome (MODS). How to protect and reduce the damage of the intestinal mucosa and how to promote the reconstruction of the intestinal mucosa have been the important topics in sepsis for many years. This study aimed to investigate the influential factors of intestinal mucosal reconstruction after intestinal epithelial injuryin vivo in a mouse model of sepsis.METHODS:Mice were subjected to cecal ligation and puncture (CLP) for induction of sepsis to assess intestinal mucosal damage, epithelial cell apoptosis, and transformed number of goblet cells, and to detect the concentration of TNF-α, IL-1 and TGF-β1 and TFF3 (trefoil factor 3) expression in the small intestinal mucosa. All above were performed by HE staining, western blot, ELISA and immunohistochemistry respectively. The experimental animals were divided into a sepsis group and a sham-operation group. The animals with sepsis were separately killed at 6 (7 animals), 24 (7 animals) and 48 hours (7 animals) after CLP.RESULTS:Injured intestinal mucosa was observed in the 3 groups under a light microscope, in which damage scores in the 24-hour and 48-hour groups were higher than in the 6-hour group and no difference was found between the two groups. Moreover, less of goblet cells or other epithelial cells adjacent to the injured surface migrated into the wound to cover the denuded area. The number of goblet cells was substantially decreased in the three CLP groups compared with the sham-operation group. Protein levels of IL-1 and TNF-α were significantly increased by 3-4 fold at all time points when compared with the sham-operation group, and cleaved caspase-3 by 4 fold. Although TFF3 expression was modestly increased for 6 hours after the onset of CLP, it appeared to decline at 24 hours and 48 hours as shown by Western blot. A similar tendency was observed upon TGF-β1, i.e. the protein level was not elevated at 24 hours and 48 hours, but increased modestly at 6 hours.CONCLUSIONS:Sepsis from CLP shows less restitution on the surface of injured intestinal mucosa. There is evidence that both constant inflammatory reaction and epithelial cell apoptosis may affect mucosal reestablishment of the intestine at the onset of sepsis. Mucosa after severe sepsis showed the state of high inflammation, and declined goblet cell function and mucosal reconstruction, which affected the repair of damaged intestinal barrier. Constant inflammatory reaction, and declined goblet cell function and mucosal reconstruction ability may affect the reestablishment of intestinal mucosa at the onset of sepsis.
ABSTRACT
<p><b>OBJECTIVE</b>To investigate the changes of the goblet cells in the intestine during the restitution process of the gut barrier after hemorrhagic shock.</p><p><b>METHODS</b>Forty-nine Sprague-Dawley rats with body weight of 250-300 g were divided into control group (n=7) and experimental group (n=42). Rats in the experimental group was further divided into 6 groups (n=7 each) according to different time point at 1, 3, 6, 12, 24, and 36 hours after hemorrhagic shock resuscitation. The specimens from ileum tissue were taken to observe the morphological chan ges of the intestinal mucosa. The number of goblet cells was determined by light microscope and/or electron microscope. The contents of trefoil factor family 3 (TFF3) of goblet cells were examined using GC-9A gas chromatographic instrument.</p><p><b>RESULTS</b>After hemorrhagic shock, mucosal epithelial injury was obvious in the small intestine. Tissue restitution was found after 3 hours, and mostly established after 12 hours. Following tissue restitution,the denuded mucosal surface was covered intensively by goblet cells. The number of goblet cells on the intestinal mucosa was reduced significantly from 243+/- 13 at 1 h to 157+/- 9 at 24 h (r=- 0.910, P< 0.01), and returned to normal level at 36 h. In the experimental group, the content of TFF3 in the intestinal mucosa increased significantly at 12 hours, decreased, but was still higher at 24 hours (t=3.24, P< 0.05).</p><p><b>CONCLUSIONS</b>The goblet cells play a key role in the restitution of intestinal mucosa. High expression of TFF3 may facilitate the intestinal mucosal restitution in the early phase.</p>